Because for humanity it is a prerequisite of survival. 因为这是人类生存的前提

276. Over three-quarters of them by hand.
     其中超过四分之三仅靠人力
277. Agriculture is like a tradition handed down...
     农业像是一种传统在汗水和辛苦劳作中
278. From generation to generation in sweat, graft and toil,
     从一代传到下一代
279. Because for humanity it is a prerequisite of survival.
     因为这是人类生存的前提
280. But after relying on muscle power for so long,
     但在长♥期♥依赖肉体能量之后
281. Humankind found a way to tap into the energy buried deep in the earth.
     人类发现了取得深埋于地下的能量的方法
282. These flames are also from plants.
     这些火焰也是来自植物

来自《家园 第一部分 Home Part1》第 279 行